Value selling is a really tool you can have in your arsenal. I would do a few things here if you're focused on having them shift to higher selling things.
(1) Articulate Value - what is the customer getting for paying more? What are the benefits they would gain with this?
(2) Teach them to place competitive traps - what are questions they could be asking their prospects to place some FUD in their minds? I have done things like "below the iceberg" documents for AEs which teach them all the things that the customer may not be thinking about in terms of all the below the surface stuff that technology needs to have in place that a more expensive solution could be (e.g. security, performance, etc.).
(3) Make sure they have the tough questions down and know how to answer it like the back of their hands
(4) Customer stories, testimonials, and references from customers who bought the more expensive products and felt it was worth it